# Elliptic point

﻿
Elliptic point

In differential geometry, an elliptic point on a regular surface in R 3 is a point "p" at which the Gaussian curvature "K"("p") > 0 or equivalently, the principal curvatures "k"1 and "k"2 have the same sign.

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• Elliptic curve cryptography — (ECC) is an approach to public key cryptography based on the algebraic structure of elliptic curves over finite fields. The use of elliptic curves in cryptography was suggested independently by Neal Koblitz[1] and Victor S. Miller[2] in 1985.… …   Wikipedia

• Elliptic geometry — (sometimes known as Riemannian geometry) is a non Euclidean geometry, in which, given a line L and a point p outside L, there exists no line parallel to L passing through p.Elliptic geometry, like hyperbolic geometry, violates Euclid s parallel… …   Wikipedia

• Elliptic coordinates — are a two dimensional orthogonal coordinate system in which the coordinate lines are confocal ellipses and hyperbolae. The two foci F {1} and F {2} are generally taken to be fixed at a and+a, respectively, on the x axis of the Cartesian… …   Wikipedia

• Elliptic cylindrical coordinates — are a three dimensional orthogonal coordinate system that results from projecting the two dimensional elliptic coordinate system in theperpendicular z direction. Hence, the coordinate surfaces are prisms of confocal ellipses and hyperbolae. The… …   Wikipedia

• Elliptic Curve Diffie-Hellman — (ECDH) is a key agreement protocol that allows two parties to estabilish a shared secret key over an insecure channel [NIST, [http://csrc.nist.gov/publications/nistpubs/800 56A/SP800 56A Revision1 Mar08 2007.pdf Special Publication 800 56A,… …   Wikipedia

• Elliptic curve — In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O . An elliptic curve is in fact an abelian variety mdash; that is, it has a multiplication defined algebraically with… …   Wikipedia

• Elliptic surface — In mathematics, an elliptic surface is a surface that has an elliptic fibration, in other words a proper connected smooth morphism to an algebraic curve, almost all of whose fibers are elliptic curves. The fibers that are not elliptic curves are… …   Wikipedia

• Elliptic boundary value problem — In mathematics, an elliptic boundary value problem is a special kind of boundary value problem which can be thought of as the stable state of an evolution problem. For example, the Dirichlet problem for the Laplacian gives the eventual… …   Wikipedia

• Elliptic orbit — A small body in space orbits a large one (like a planet around the sun) along an elliptical path, with the large body being located at one of the ellipse foci …   Wikipedia

• elliptic geometry — noun (mathematics) a non Euclidean geometry that regards space as like a sphere and a line as like a great circle Bernhard Riemann pioneered elliptic geometry • Syn: ↑Riemannian geometry • Topics: ↑mathematics, ↑math, ↑maths …   Useful english dictionary